'Is it a bold contemporary design or a garden shed?' John and Terri found themselves asking, halfway into their build. They had knocked down a derelict house in a beautiful rural setting and commissioned commercial architects to build them a new one. But was it too small for them, their young son and the baby on the way?

The 1930s derelict water-works Chris and Leanne fell in love with was huge and its design had clearly been inspired by Gilbert Scott's Bankside power station, now better known as the Tate Modern. But nothing would deter the couple. 'We looked at it,' said Chris, 'and saw our home.'

For 10 years, Ben lived in tents and caravans in a wood in West Sussex. As a woodsman, he needed and wanted to live among the trees. But after a battle with planning he finally got permission to build himself a house with more creature comforts. He invited volunteers to help him build one by hand, from the materials growing around him.

For Philip and Angela, the build was part of a life change that had begun two years earlier. Just after their second daughter was born, Philip fell seriously ill, prompting the family to leave London and move back to his parents' village. Acquiring the site was easy, as Philip's parents owned it. Getting planning permission took longer, and a crucial factor in their success was that they would be restoring the outside of the barn and keeping the innovation hidden

Tom and Judy wanted more than just a home for themselves and their two children. On a site of outstanding natural beauty in Buckinghamshire, they set out to build an ambitious house - a symphony of angles, glass walls and exposed steel, with a dramatic inverted roof. Tom made himself site manager and main contractor. He had no experience but he liked a challenge - and, after all, how difficult could it be?

After 10 years of living in a small house in east London, John and Eleni hankered after modern, open-plan living. They didn't want to move, so they decided to give their Victorian terrace home a radical redesign. The house was in a conservation area, so the outside had to remain unchanged. Inside, however, they decided to rip out everything including walls, ceilings, floors and start again.

The old quarry stood on a slope of the Eden valley and commanded beautiful views. Local architect John Bodger designed a two-storey house that burrowed backwards into the rock and made maximum use of natural resources for light, warmth and power

Merry's family have been Herefordshire builders for generations, so she knew that the county was rich in traditional building crafts. She and Ben decided to combine these with technology for a new house with a genuinely rural feel. Her father drew up a design that followed the traditional cottage layout while incorporating modern comforts.

Kevin McCloud returns to the Lambourn Valley to meet a couple who took three years to finish building their home on the Berkshire Downs.

Kevin McCloud revisits the improbable build of two architects who built their central London house out of straw bales, springs, nappy cladding and silver tin.

Kevin McCloud revisits a couple who converted a disused electricity substation in Sunderland into a four-bedroom family home, armed with just £50,000 and ideas from a book about Moroccan interiors. Despite a number of setbacks, Anne and Richard Curtis created a living space which, three years later, has had a sumptuous rooftop garden added to it.

Kevin McCloud revisits retired couple Denys and Marjorie Randolph, who decided to embark on their final building project, a brand new green oak barn-style house.